117 lines
2.6 KiB
C
117 lines
2.6 KiB
C
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/*
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* Mach Operating System
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* Copyright (c) 1991,1990 Carnegie Mellon University
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* All Rights Reserved.
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*
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* Permission to use, copy, modify and distribute this software and its
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* documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
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* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*/
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/*
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* HISTORY
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* $Log: db_access.c,v $
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* Revision 1.1 1992/03/25 21:44:50 pace
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* Initial revision
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*
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* Revision 2.3 91/02/05 17:05:44 mrt
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* Changed to new Mach copyright
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* [91/01/31 16:16:22 mrt]
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*
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* Revision 2.2 90/08/27 21:48:20 dbg
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* Fix type declarations.
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* [90/08/07 dbg]
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* Created.
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* [90/07/25 dbg]
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*
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*/
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/*
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* Author: David B. Golub, Carnegie Mellon University
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* Date: 7/90
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*/
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#include "param.h"
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#include "proc.h"
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#include <machine/db_machdep.h> /* type definitions */
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/*
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* Access unaligned data items on aligned (longword)
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* boundaries.
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*/
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extern void db_read_bytes(); /* machine-dependent */
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extern void db_write_bytes(); /* machine-dependent */
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int db_extend[] = { /* table for sign-extending */
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0,
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0xFFFFFF80,
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0xFFFF8000,
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0xFF800000
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};
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db_expr_t
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db_get_value(addr, size, is_signed)
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db_addr_t addr;
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register int size;
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boolean_t is_signed;
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{
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char data[sizeof(int)];
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register db_expr_t value;
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register int i;
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db_read_bytes(addr, size, data);
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value = 0;
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#if BYTE_MSF
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for (i = 0; i < size; i++)
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#else /* BYTE_LSF */
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for (i = size - 1; i >= 0; i--)
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#endif
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{
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value = (value << 8) + (data[i] & 0xFF);
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}
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if (size < 4) {
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if (is_signed && (value & db_extend[size]) != 0)
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value |= db_extend[size];
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}
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return (value);
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}
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void
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db_put_value(addr, size, value)
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db_addr_t addr;
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register int size;
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register db_expr_t value;
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{
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char data[sizeof(int)];
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register int i;
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#if BYTE_MSF
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for (i = size - 1; i >= 0; i--)
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#else /* BYTE_LSF */
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for (i = 0; i < size; i++)
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#endif
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{
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data[i] = value & 0xFF;
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value >>= 8;
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}
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db_write_bytes(addr, size, data);
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}
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